Rotary internal-combustion engine



ROTARY INTERNAL-COMBUSTION ENGINE BY' MAWLMAW ATTORNEYS March 14, 1950 J. N. HINCKLEY 2,500,458

ROTARY INTERNAL-COMBUSTION ENGINE Filed July 25, 194e :s sheets-sheet 2 iff-2 I rNvENToR Jaf//v /V. Hwa/Ley BY MMU) www ATTORNEYS Ml'h 14 1950 J. N. HINCKLEY 2,500,458

' ROTARY INTERNAL-COMBUSTION ENGINE Filed July 25, 1946 3 sheets-'sheet 3 INVENTOR JOHN/1( ///fvc/mfr ATTORN EYS Patented Mar. 14, Q

UNITED STATS PATENT OFFICE 8 Claims.

This invention relates to internal combustion engines of the rotary type, such as disclosed in Hinckley and Clark Patent No. 2,060,937, patented November 17, 1936, although some features are notI necessarily limited to such use.

The prior patent discloses a rotary engine made up of a plurality of short cylinders, each of which comprises a cylindrical casing with a cam-shaped rotor disposed therein; the casing has pivoted at its cylindrical wall two arms bearing upon the drum surface of the rotor. Each arm has a backwardly extending sector blade or horn which separates the expansion chamber from the compression chamber; each arm also has a blade portion riding on the rotor and sealing the combustion chamber at proper times. The admission of gas and the disposal of exhaust is accomplished by suitable valves located around the periphery of the casing. In general, inward movement of the arms caused by an explosion of gas draws fresh gas into the separate compression chambers while the outward movement of the arms compresses this fresh gas, after which the compressed gas is led through suitable valves to another and separate cylinder where the combustion chamber of an appropriate arm is ready to receive it. After the gas is exploded, pushing the arm inwardly and exerting pressure on the blade end of the arm and the rotor, an exhaust valve opens and further movement of the rotor scavenges the expansion chamber.

The present invention eliminates the transfer of :compressed gas from one cylinder to another and makes each cylinder a complete operating unit in itself; it provides for three or more arms in each cylinder. Gas compressed in the combustion chamber of any arm is fed back to the combustion chamber of the immediately preceding arm which is ready for the explosion event.

The present invention also provides for greater efficiency, smoother operation, simpler construction, improved sealing, lubrication, cooling, and valve action.

The invention also consists in certain new and original features and combinations hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part hereof, in which ,v Fig. 1 is a section taken radially through the motor on the line I-I of Fig. 2, the section being irregular to show different details of construction in the various parts of the motor;

Fig 2 is an irregular section on the line 2--2 of Fig.) taken to illustrate different parts of the motor;

Fig. 3 is an edge View of one of the arms illustrating the sealing strips;

Fig. 4 is a section on the line 4--4 of Fig. 3 through the main stem of the arm;

Fig. 5 is a detailed section through the edge of the rotor to illustrate the sealing strips;

Fig. 6 is a longitudinal view of the combustion chamber sealing strips of Fig. 5 illustrating the wavy spring;

Fig. 7 is an isometric View of an arm to illustrate the cooling passages, the sealing strips being omitted for simplicity of illustration; and

Fig. 8 is a section through the seal for the combustion chamber.

In the following description and in the claims, various details will be identified by specific names for convenience, but they are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and forming part oi' this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified in various respects without departure from the broad aspect of the invention.

Referring now to the drawings, the motor is made up, generally, of a case comprising a cylinder blo-ck I0 having removable heads II and I2 enclosing a rotor chamber containing a camshaped rotor I3 mounted on main shaft I4 which is journaled in the heads. Overhanging on shaft I4 is an output element 20 which may be either a pulley or gear and which may also act as a ilywheel. J ournaled at the peripheral wall of the rotor chamber are three arms I5 bearing against the cam surface of the rotor I3. Suitable valves control the events, including intake valve I6 which controls the flow of fresh combustible gas mixture into the compression chamber; spring pressed automatic discharge valve Il which controls entry of the compressed gas into the compression conduit; inlet valve I8 which controls entry of gas into combustion chamber, and exhaust valve I9.

The motor is shown for purposes of illustration as comprising three sections A, B and C (shown for convenience as divided by radial lines X, Y, Z) each one of which is subjected to a complete thermo-dynamic cycle. Since the parts oi each section A, B and C are identical in construction, the same reference characters will be used in the several sections, and since the several sections are shown at variouspoints in their thermodynamic cycles, they will also be used to illustrate the several events of a single section.

In general, as the rotor I3 rotates in the direction of the arrow R, the cam surface thereof causes the several arms I to reciprocate back and forth. The movement of these arms, together with appropriate movement ofthe several valves, causes fresh gas to be drawn into the motor, the gas then to be compressed, exploded, expanded and exhausted at proper times.

Although three sections are shown for pur poses of illustration, it will be understood that any multiple of three may beused. The three section form shown provides a power impulse at each 120 of revolution or" the motor shaft and thus is similar in this respectto a conventional six cylinder internal combustion engine.

The case block I0 is shown as a one piece casting although it may be cast in sections separable along radial lines and suitably bolted together. It comprises an outer circumferential wall 23 having a suitable water jacket space indicated in general by 24 cast therein. This jacket space 24 Icommunicates with jacket spaces cast in the heads and surrounds all critical parts of the case so asto provide proper cooling action. Suitable inlet and outlet passages are provided in the heads orA block or in all three members for circulating the coolant. The cast block I'I is shown resting on a cast base 22 to which it-is suitably bolted.

Secured to the block I is an intake manifold 25 leading to the several intake valves It. The intake` manifold 25 communicates with a suitable carburetor (not shown) for'mixing air with the fuel gas which may be gasoline or illuminating gas, for example. The exhaust valves I9 are shown leading directly to atmosphere although it will be understood a suitable exhaust manifold may be provided for disposal of exhaust gases.

The block III is provided withV passages 3i communicating with the intake manifold 25 and with the interior of the case. seat 3E for the valve disc 27. Disc '2l has stern 28 slidable in a sleeve 29 suitably secured to the casting.

Suitably formed in the block Il)l are exhaust passages 38 having seats 3l for the discs 34 of exhaust Valves I9. The valve has a stem 35 slidable in sleeve 36 which is suitably securedto the casting.

The block IIlhas seats 40` for automatic discharge valves Il'. 'Seating 'against seat 45 is disc 49 slidable in sleeve 42 which Ais suitably afxed tothe casting. Spring' 43 normally urges the valve into closed position. Sleeve 42 has open# ings leading to compression passages 44 to convey compressed gas mixture to the combustion chamber as discussed below.

Compression passages 44 are cast into block III and lead from the automatic discharge valves I'I` to inlet valves I8 of the 'preceding section; that is to say, from the automatic discharge valve II of section C, for example, to the inlet valve I8 of section B.

Case block I0 also has horn recesses 41, each recess being laid out with its corresponding wrist pin 6I as a center. These recesses are for the horns 65 of the several arms I5 for a purpose explained hereinafter.

Case block Ill also has seats for suitable spark plugs 48 which project into combustion chambers 50 opposite the gas inlet points controlled by the inlet valves I8.

The inlet valves I8 each comprises a valve' housing 52 seated inv a recess 5I inthe block it opposite the spark plug 48. The valve housing 52 has a seat 53 for valve disc 54 having stem 55 which is slidably mounted in the valve housing Each passage 3i has a- 4 52. The passage of stem 55 through the valve housing 52 is sealed by a suitable gland 56 and the Valve housing 52 is held in position by a holddown ring 5'! suitably bolted to the block I, one of the bolts being indicated by 58.v

Each arm I5 has a bearing portion 65 journaled on a hollow wrist pin 6I and a blade portion 62 having double curvature 53, 64 for special cooperation with the cam surface on rotor I3 as explained hereinafter. Projecting outwardly from the blade 62 is the horn 55 which reciprocates in the horn space 41.

As stated above, the heads II and I2 are detachably bolted to the block IU. Referring first to back head II, this head is of generally flat or disc formation and has'a lwater jacket space 66 communicating with the jacket space in the block. It has a shaft bearing 6l for the main shaft I4 and a recess 68 for the counter-weight 69 keyed to shaft I4. A detachable cover plate lt closes the recess 58. The back head II has space for spark plugs 48 and for intake manifold 25. Back head l also has recesses 1I for the wrist pins 6I.

The front head I2 is also bolted to the block and is generally plate or disc shaped. It has water jacket space i4 communicating with the water jacket on the block. It has a bearing 'I6 for main shaft I4 and seats 'I5 for Wrist pins 6I. It has a recess for counterweight TI suitably keyed to main shaft I4.

The counterweights 69, 'I'I counter-balance rotor i3 to place the rotating parts in static and dynamic balance, thus minimizing need for a ywheel.

It will be noted that each section A, B, C is controlled by four valves, three of which are positively operated poppet valves and the other is an automatically spring operated check valve. A valve rigging is provided for operating the positively operated poppet valves. This valve rigging comprises two drum cams 18 and I9 affixed to the main shaft I4 and a face cam 8D keyed to main shaft I4. Drum cams 18, 'I9 are for the intake valves I6 and exhaust valves I9; face cam is for inlet valves I8.

The valve rigging also comprises tappet housing -82 suitably bolted to the front head I2 and having a detachable outer plate 83. Plate 83 has a shaft bearing 84 for shaft I4 which supports the power transmitting gear or pulley 2U in overhanging relation.

The drum cams 'I8 and 'I9 each operate three radially extending tappets, only one of which (BI) is disclosed for purposes of illustration and that operating intake Valve I6. The radial tappet BI comprises a mushroom follower 85 secured to slide 8l which is slidable in the housing 82.` The tappet 8l operates a rocker arm 83 fulcrumed on a bracket secured to the front head I2. Rocker arm 88 abutsvalve stem 28to open the valve I6 against the tension of valve springBS. Valve tappet 8| engages rocker arm 88 through a ball-socket joint 9i and has a suitable adjust-v ment 92 for adjusting valve clearance, as will be' understood. `1

It will be understood that, as the main shaft I4 rotates, suitable rise on cam 'E8 will raise the tappets 8| to open the several intake valves I5 at the proper times. Similarly, rise on drum cam 4'I9 will operate similar tappets to open the several exhaust valves I9 at the proper'times.

The face cam Sil for operatingthe axially ex# tending inlet valves I8 drives a plurality of rollerv followers S8. one for each inlet valve, each roller 98 being journaled on a rocker arm 96. three rocker arms 96 are each fulcrumed on a shaft 91 seated in the tappet housing 32. Each rocker arm 96 has a tappet 95 which engages the valve stem 55 to open the inlet valve I8 against the pressure of valve spring 99. A lock nut locks the adjustable tappet 95 in adjusted posi-l tion after tappet is adjusted to give proper valve clearance, as will be understood by those skilled in the art.

As the shaft I4 rotates, a rise on face cam 80 operates the three follower rolls 98 to open the three inlet valves I8 at proper times.

The rotor I3 comprises a hub IOI suitably keyed to the main shaft I4, a web |02 and a drum |03 having a specially shaped cam surface which cooperates with the internal surface of the block and the inner surfaces of the arms I as discussed below. Each arm has a conical spring |04 seated in a recessed seat |05 in the block and in a seat |06 in the arm to insure holding the arms against the rotor.

The moving parts are suitably lubricated and sealed against the gas pressures. The arm hubs 60 are sealed by a plurality of spring-pressed flat strips |09 seated in grooves in the block and bearing against the cylindrical surface on the hubs 60. Similarly, the outer surfaces of the horns 65 are sealed by a plurality of flat strips I0 seated in suitable grooves in the` block. It will be noted that only the outer surfaces of the horns 65 remote from the wrist pins 6I are sealed and that there is a slight clearance between the near surface |0'I of the horns 65 and the walls of the horn recess 4l (see Fig. 3).

The edges of the arms (Figs. 3-6) are sealed by sealing strips II2, IIS, and |4| which resiliently bear against the flat walls of the end heads. The strips I 40 and I4I are of flat stock and seat in corresponding grooves in the arm as indicated by |40' in Fig. 4. The strips ||2 and ||9 are of angular cross section and seat in correspondingly shaped slots, as indicated by |I2 in Fig. 4.

The two flat strips |40 follow the stem 62 of the arm and the horn 65 as indicated in Fig. 3. The flat strip I4I connects the flat strips |40 just mentioned and follows 4the end 59 of the arm. The angular strip ||2 follows the stem and end of the arm. The angular strip ||9 follows the horn andv end of the arm. Additional seals indicated in general by |42 may be placed in the walls between the several strips.

The edge of the rotor drum |03 (Fig. 5) has a flat stock sealing ring |44 and an angular sealing ring |43 both following the periphery of the drum |03 and extending entirely laround the rotor. These are seated in correspondingly shaped recesses and bear against the flat surfaces of the casing heads.

It will be understood that all of the several 'sealing strips have wavy spring stripsseated in the bottom of their respective grooves for yieldably urging these strips against their cooperating surfaces to provide eflicient sealing.A The wavy spring is illustrated at |45 in Fig. 6 which illustrates the seal for the explosion chamber 50.

The seal for the combustion chamber (see alsoFig. 8) comprises a channel shaped strip III and an L-shaped strip ||3 cooperating with a projection I|5 on thecasing to limit the outward movement of the combustion chamber seal under action of its wavy spring. The tip bevels 4|25 on the arms- I5 seat against thesese'als Iy I I, H3.

TheA

The motor may, of course, be lubricated by" mixing lubricating oil with the gasoline or otherwise introducing it into the gaseous mixture fed into the intake manifold 25 in a manner similar to the lubrication of certain well-known two cycle engines used, for example, for outboard motors for boats. However, the motor may have a positive lubrication system which may be used either alone or in conjunction with a lubrication system depending upon mixing lubricating oil with fuel.

The positive lubricating system comprises a plurality of oil feed ducts ||4 in head I2 leading to the three hollow wrist pins 6I. Similar oil ducts (not shown) in head I I lead from the wrist` pins 6I so that constant oil circulation may be provided. The wrist pins are drilled only part way through, providing a partition II'I separating the axial hole into inlet and outlet ends |53 and |54 having suitable radial openings IIB. Openings IIB lead oil `to the bearing surface between arm bearing 60 and wrist pin 5| which is fast in heads II, I2; they also communicate with cooling ducts |50, I5! (Fig. 7) opening into the said bearing surface and extending through the length and breadth of the arms and horns.

These cooling ducts may have any suitable arrangement but in general one duct |50 leads from one axial end |53 of the wrist pin, lengthwise of the arm, across the tip of the arm back the other side to the other axial end |54 of the wrist pin. A second duct l5! passes from one axial end |53 down the blade of the arm and into the horn 65, across the end of the horn and back to th-e other axial end |54. These cooling and lubricating passages may have suitable filamentary connections (not shown) with the several sealing strips and with the arm bevel |29 for lubricating the areas of Contact of the arms with the case and rotor.

Operation It will be noted that the rotor I3 has a high portion or dwell |20 of substantially constant radius extending through an angle of approximately 120. The remaining 240 comprises a rise |2I leading from the dwell |20 to low point |22 of the cam and a fall |23 leading from low point |22 to the dwell |20 of the cam. The outer curved portion 64 of the arms |5 cooperates with the dwell |20 of the cam, as shown at arm of B, while the inner curvature 63 on the arms cooperates with the nose |24 of the rotor cam during part of compression.

The tip of the arms I5 has a bevel surface |25 which cooperates with the tip seal III to seal the arm against the casing as illustrated .in the position B of the arm. This closes the passage connecting with combustion chamber 50. The block has recesses |26 adjacent the intake valves I6 to house the arms when in outermost position while it has projecting portions |21 adjacent the exhaust valves I9 laid out on a radius equivalent to the maximum radius of the rotor.

In operation, as the rotor rotates in the di'- rection of the arrow R, it causes the three arms I5 to 4execute an oscillating movement, the arms occupying an innermost position when engaging the low point |22 of the cam (near position C) from whence the arm rides up on the rise |2| of the cam until it occupies an outermost position, as shown in position B. Continued'rotation of the rotor causes dwell |20 to hold the arm in substantially this outermost positionl until the tip '|28 of rotor reaches the tip of the arm (near o'stiomA) when the arm: rides down:` onI the fallv |23- of the rotor* to the. lowermost position |211: (near position C).

It willV be understood that each arm Iv forms part of a section which goes through a complete thermo--dynamicV cycle. Each arm i5 has four valves' associated with it. Intake radialv valve Hi passes fresh gas drawn from the supply into the compression chamber iti. Automatic dis,- charge. Valve passes compressed: gasV from the compression chamber l3| through compression passage. dit. to the inlet valve I3 of the next preceding section. Inlet valve i8 admits compressed gas to the combustion chamber 50 which gas is led tothe expansion chamber 32, doing Work. against the arm I5y and. against the rotor |3 until the gas reaches the end of its expansion, at which time the exhaust valve i9 opens, passing inert or burnt gas from the expansion chamber |32 to exhaust.

Thel three arm type turbo-motor as shown is. equivalent to a conventional six cylinder recipro-v cating internal combustion engine. using the Otto cycle; Each section A, B, C, fires once each revolution giving a power impulse every 120 of straight' drive shaft rotation. The cycle of the present invention. differs from the Otto. cycle in thatv the.- gas is compressed on one side of the arm and exploded'. and expanded on the other side of the arm, which has certain advantages discussed below.

Each section A, B, C, goes through an identical cycle. so only one cycle will be. traced. However, the cycle of each. section is not complete in itself buteach section receives compressed gas from the next preceding section. Since the different armsv l5 are shown at different points in their cycles, theser arms will be used to illustrate the several events of a single cycle.,

It will be noted that rise |2| pushes theY arms outwardly for compression while fall |23, down which the arms ride, provides the pushing surface propelling the rotor during expansion.

It should bev noted that rise [2| and fall |23 are independent so that various rates of comhaust `valve I9 and has just compressed gas in its compression chamber for use of section A. Arm of C is shown in the position of almost com-.- pleting its expansion cycle and almost completing the drawing of fresh gas into its compression chamber |3|.

As the rotor |3 revolves clockwise in the direetion of arrow R, arm of A will follow the rotor under the impetus of :an explosion in its combustion chamber 51| and draw fresh gas through intake valve |5 into compression chamber |3|. After the arm of A reaches its innermost position, the intake valve IE oi A closes.

As the rotor continues to rotate, arm of A is forced back to its outer position which compresses the mixture in its compression chamber |3| and forces it through automatic discharge valve |3 and through compression duct t4 to the combustion chamber 5D of section C. The combustion chamber inlet valve |.8 of section A is closed approxmately 30 before `the tin 1.28ct therotor As the .l

reaches' theend of the: compression arma of i Ignition takes place by the spark plug. 48 of A firing approximately 7 to 15 before the tip ljof therotor passes ther end of the arm of A.

AsV the tip |28 of. the rotorfpasses beyond. the end of arm A, thel force of the expansion in combustion chamber 50 acting uponv the area of the. varm' and upon the area. of the. rotor,V forces the arm to follow the rotor.

The exhaust function takes place by the ionward surface |21 of the: rotor sweeping, beforeit the. burnt gases out of the' expansion chamber through the exhaust valve |9. Asarm of Abegins itsl inward movement., section C' is almost ready for its exhaust valve |9 to openLthe exhaust valve opening when the tip |28 of therotor passes about 50. past the tip of arm of section A, thusv providing overlapping expansions (of sections C and A) simultaneously on the rotor. Inlet. valve |81 of section C may open. just before arm of Cr seals against seal to help scavenge eonibus tion chamber and expansion chamber of C1. The exhaust valve closes when the exhaust chamber volume becomes substantially zero.

Thus an. internal combustion engine: has been described which has. a minimum of rotating and reciprocating parts. The simple oscillating arms acting on the. rotor perform all of the functionsv ofpistons, connecting rods, yand bent up: cranlrP shafts of the conventional engine. There is. less vibration, the. drive. shaft is` straight and may' be carried on ball or roller bearings. The one-- roten, threeearrn motor firesA asotten asa convene tional six cylinder engine with its six pistons, si); connecting rods, six cranks, etc.

Thev compression,l combustion and .expansion chambers are: separate. This permits utilization of expansion to a much lower pressure and ternperature thereby appreciably increasing the therrnal eiciency. Expansion is not restricted by limitation of the compression ratio. The compression ratio may be made suitable for DieF sel requirements. The expansion ratio may be greater than the compression ratio as in the Atkinson cycle. The expansion ratioA may be double the compression. ratio.

Due to the. construction of the present turbo motor, the eiliciency of the Atkinson cycle may be obtained with the simplicity of Ottovor Diesel cycles construction. Due toA thegreater expansion and consequently lower temperature, there is less heat iiow from the combustion and expansion chambers to the water jacket.

The ideal cold spherical combustion chamber entirely contained in. one casting is obtainedF hot gases from the combustion chamber into the expansion` chamber. The combustion`v chamber provides for maximum turbulence, thus mini-miaing detonation. kIt is completely surrounded by Water-and has only one valve, which is cooled by each incoming charge.

Improved scavenging is obtained. The inlet poppet valve may be opened slightly before the arm` seals the combustion chamber, thus expella ing burnt gases.. After the gases` in the ,expane sion chamber have expanded to from. nine to twelve times their original volume and areneaxf atmospheric pressure, the exhaust valve opens and remains .open until the rotor has expelled all the waste gases from vthe. previous power impulse. The exhaust valves arel not ,subjected to pressure or to high temperatures when exhaustng.

f There is increased power overlap with the present' construction. pulses for each revolution of the rotor and the gas in any section res and expands before the expansion of a previous section is completed, thus providing two expansion chambers operating upon a rotor at the same time. Thus more uniform torcue is obtained. vi The increase in the number of arms to three gives more pumping volume than obtained with a two arm cylinder as in the prior patent above referred to.

The force required for compression by action of the forward side of the rotor upon the arms is obtained by expansion directly applied 'to the rearward side of the rotor. This reduces ny- Wheel need and lessens stress on the main shaft. vThere is less likelihood of kickback because there is' approximately a'195o lock. After each power impulse the arm is locked as by a togglev joint `so that it is impossible vto reverse the direction of rotation of the rotor by applying pressure on the compression arm. Compression takes place in about 90 of shaft rotation after which there is no pressure on the compression arm forabout 120.v

The compression conduit connecting the compression chamber with the preceding combustion chamber may hold about one-fifth of a charge lby volume. This mixture remains in the passage- :way under compression for about .02 of a second at 1200 R. P. M. It cannot burn until it is transferred to the combustion chamber. It is completely surrounded by water and there is no possibility of pre-ignition.

The arm and rotor surfaces are subjected to a `minimum of wear. These surfaces may be made from extra hard material havingr long wearing and high heat resisting qualities. The free ends of the arms where they engage the rotor can wear considerably requiring only minor timing adjustments.

The wear on the arms, as well as vibration, is minimized by inherent construction of the motor. the power stroke on the same arm, assists in reducing the bearing load of the free end of the arm against the rotor during the highest pressure period. Other provisions may be made to minimi'ze wear and vibration, such as exhaust valve timing, compression arm design and ignition timing. For example, leaving the exhaust valve of any section closed until the power stroke of that section has expanded over 160 maintains a cushioning effect on the next arm as it is starting on 4a new power stroke. Making the free end of the arm of such size, that the pressure on the total area exposed is just great enough to compel the arm to follow the rotor and maintain a gas seal between the arm and rotor on the pres- .sure side, minimizes initial power impulse pressure 'on the arm. As the end of the arm wears, such wear can easily be compensated for by advancing the ignition.

Sealing between the edges of the arms and the casing head is efficiently accomplished by the :sealing strips lcarried by the arms; likewise seal- .jing between thev end faces of the rotor and the ,-.headsl Sealing between the cam' surface of Athe trotorj andltheylindrical surface of the block` is of secondary importance since pressure areas on the rotor are always bounded by the arms. The arm ybearing sealing strips i110, the horn seal- ;ing stripi l0, the combustion chamber `sealing There are three power im` The suction, occurring simultaneously with l0 strip ll I, all extend axially of the block from head to head.

The intake compression, combustion and expansion chambers are sealed against leakage by the sealing strips being forced out against the opposing surfaces by the wave springs behind them. These sealing strips also take care of expansion of the relatively moving parts which retain proper working clearances at all times. The sealing strips on the rotor always travel in the same direction and thus are not subjected to increased friction due to sudden change in di'- rection. The rotor does not do any of the pumping or compressing but all pumping andv compressing Ais done in the separate compression chambers bythe oscillating arms which act as built-,in compressors:

The enginelis-adequately cooled both by Water jacketsand by oil iiow through the arms. Heat transfer also takes place by contact of the arms and rotor, through their sealing strips, with the water cooled casing walls. All vital parts in the casing, including all passageways, combustion, compression and expansion chambers, are surrounded by water.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

l. In a rotary -internal combustion engine, a case having an annular wall with fiat ends pro'- viding a central,` generally cylindrical rotor space, said ends carrying central bearings, a main shaft journaled in said bearings, a rotor on said shaft having a cam surface, three arms, means pivoting said arms at the outer side of said rotor space at equi-spaced points, each said arm having a blade portion riding on said cam surface and an outer horn, said case having a horn recess for said horn, said horns dividing said space into three compression and three expansion chambers, ignition means for expanding gas in each expansion chamber while thegas in the preceding expansion chamber is still expanding.

2. In a rotory internal combustion engine, a

.case having an annular Wall with flat ends providing a central, generally cylindrical rotor space, said ends carrying central bearings, a main shaft journaled in said bearings, a rotor on said shaft having a cam surface, three arms, means pivoting said arms at the outer side of said rotor space at equi-spaced points,l each said arm having a blade portion riding on said cam surface and 'an outer horn, said case having a horn recess for said horn, said horns dividing said space into ycompression and expansion chambers, conduits f having seats, hollow wrist vpins in said seats, arms cesses for said horns, said hollow wrist pins having vcentral walls forming inlet and outlet parsages, radial inlet and outlet openings in said almanac `lil lWrist pinsv connecting said passages, said hubs having inlet and outlet openings adapted to register with corresponding Wrist pin openings, said :arms eachvhaving conduits connecting hub inlet and outlet openings, at least one of said conduits extending to the free end of said blades,4 at leastanother of said conduits extending to the free ends of said horns.

4. In a rotary internal combustion engine, :a :case having a generally cylindrical Wall with ilat heads forming a rotor space, a main shaft centrally journaled in said heads, a rotor on said shaft and havinga cam surface, said cam ysurface comprising a rise, a ldvvell and a fall, said cylindrical surface `having three recesses, three wrist pins in said recesses secured to said case, three arms on said Wrist pins, each said :arm hav.-

Y 'ing a blade `riding onsaid cam surface, each ysaid arm having a horn :laid out With .its Wrist pin as a center, said .block having three horn recesses for said horns, said .oase having three vspherical combustion chambers, 'said horns dividing said rotor space into three compressionchambers and three expansion chambers, compression passages connecting the combustion chambers with :the next preceding 'compression chambers, valves at the junction of said compression passages and combustion chambers, rsaid case having three inlet passages, inlet valves in said inlet passages Vat the'junction of said inlet passages and the compression chambers, valves in said compression passages at their junction 'with said compression chambers, said rotor chamber having beveled seats at the junctures of the 'expansion and combustionchambers, sealing devices iii-said r`shaft and having a cam surface, 'said cylindrical surface having a plurality of recesses, wrist pins in said recesses and secured "to said case, arms on said wrist pins, each 'said arm having .a blade riding on said cam surface and having an outer curvature concentric Withthe main shaft and an inner curvature separated by a high point, said arm havinga horn laid .out with its kWrist pin as Ia center, said block having horn recesses for said horns, said ,case having spherical .combustion `chambers entirely cast therein, 4said horns dividing the chamber :space into compression chambers and expansion chambers, compression passages connecting the ,combustion chambers with the next preceding compression chambers, axial poppet valves at the junction of said compression passages and combustion chambers, saidcase having inlet passages, radallyextendinginlet poppet valves in said inlet passages at the junction of said inlet passages and the compression chambers, f

radially movable check valves in said compression passages at their junction with said Ycompression chambers, said rotor chamber having Ibeveled/seats atv the junctures of the .expansion and combustion chambers, sealingdevices in said Seatssaid blades havingbeveled surfaces seating'against'said seatsY to seal off periodically Ithe :combustion chambers.

6. In a rotary internal combustion engine, a case having an annular Wall with end lwalls providing a central, generally cylindrical rotor space,

ing arm, whereby the single case houses a com plete operating unit.

7. In .a rotary internal combustion engine, a

.case having an annular'wall with zend Walls pro-` -Viding azcentral, general-ly cylindrical rotor space, `a rotorv journaled in saidzspace and having a caro drumsurface, a plurality of arms'means pivoting saidarms `at the outer side of said'rotor space, `each said arm .having a blade portion riding on said cam surface and ank outer horn, saidcase having a horn recess for .said horn, said horns dividing said space into compression and expansion chambers corresponding to the vnui'nber o! arms, said engine having means for causing the gas to expand in .each .expansion chamber while the gas in the preceding expansion chamber is still expanding.

l. In a rotary internal combustion engine, ,a case Yhaving an annular Wall with end Walls providing a central, generally cylindrical rotor space. .arrotor having a cam surface journaled in ysaid rotor space, :an arm pivoted to the outer side of said rotor space, said arm having a blade portion riding on said cam surface :and .an outer horn,

said case having a horn recess for said horn, :said

horn dividing said spacev into a compressionand van yexpansion chamber, said case having a `combastion chamber adjacent said horn recess and communicating with said expansion chamber, said case having a recess adjacent said combos tion chamber to house said arm, the tip of said arm being beveled to seat against a corresponding beveledseat on the case, said beveled ,seat having a slot extending from end toend vof the rotor space, said slot having a projection lon a side Wall thereof, .a sealing strip of L-shaped .cross section seated in said slot, a sealing .strip of channel shaped cross section nested in the L-shaped strip and having itschannel .surrounding said proies-1 tion, and a wavy springbetween .the L-shaped strip and the bottom of the slot to urge said sealing strips Vagainst said tip.

JQHN HINCKLEY.

REFERENCES CITED 'The following vreferences are of record in the 'le ci this patent:

muren .sfrafrss ,PATENTS Number Name ,Date

654,721 Flint Juli/31,190!) 920,678 Smith `May 4, 1909 943,592 'Braley Dec. 14, V1909 1,145,161 Mears July 6,1915 1,145,627 Stradovsky July 6, 1915 1,242,693 Hibner Oct. 9, 1917 '1,766,005 Sullivan June 24, 1930 2,060,937 Hinckley Nov. 17, 1936 2,343,948 Bellazini Mar. 14, 1944 25349,'481 Wallace May`23, F1944 FOREIGN PATENTS Number Country Y Date .355,708 Great Britain Aug. 24, 1931 

